ISO/TC 193/SC 1/WG 17 - Analysis with Associated Uncertainty

This document specifies a text file format - XML file format - for reporting natural gas analysis results and other data relevant to natural gas. The file name is applicable when it includes the extension of .XML (case insensitive). The XML file format is useful for output from ISO 6974-1[1] for composition and ISO 6974-2[2] for uncertainty, for input for ISO 6976[3] and for input for ISO 10723[4] for performance evaluation. Typically these would be the gas composition as provided on an analysis certificate, or results from a performance evaluation that would be read into an Excel spreadsheet for data processing.

This document describes the precision that can be expected from the gas chromatographic method that is set up in accordance with ISO 6974-1. The stated precision provides values for the magnitude of variability that can be expected between test results when the method described in ISO 6974-1 is applied in one or more competent laboratories. This document also gives guidance on the assessment of bias.